Electrical press.



Patented Mar. 25, I902. 0. KAMMEBER.

ELECTRICAL PRESS.

(Application filed May 19, 1900.)

2 Sheeis$heet I.

(No Model.)

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Patented Mar. 25, I902.

0. KAMMEREB.

ELECTRICAL PRESS.

(Application filed m 19, 1900.

2 Sheets$heot 2.

(No Model.)

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UNITED STATES PATENT OE IcE.

OTTO KAMMERER, OF CIIARLOTTENBURG, GERMANY.

ELECTRICAL PRESS.

SPEflIFIGATION forming part of Letters Patent No. 696,053, dated March 25, 1902.

Application filed May 19, 1900.

To ZZ whom it may concern:

Be it known that I, Orro KAMMERER, a subject of the King of Prussia, German Emperor, and a resident of 148 Berliner street, Oharlottenburg, near Berlin, in the Kingdom of Prussia, German Empire, have invented a new and useful Improvement in Electrical Presses, of which the following is an exact specification.

My invention relates to presses which are set in motion by electrical power.

The purpose of this improvement is to secure the electromotor against any damage. I obtain this efiect by using a fly-wheel arranged on the axle of the electromotor and by using a disconnecting mechanism for the electromotor.

In order to make my invention more clear, I refer to the accompanying drawings, in which similar letters denote similar parts, and in which- Figure 1 shows a diagram of the resistances during the press operation. Fig. 2 shows a diagram of the active power of the electromotor in proportion to the resistances which are to be overpowered during the press operation. Fig. 3 shows a vertical section of a press provided with the improvement. Fig. at shows a vertical section of a press with a modified form of the improvement. Fig. 5 shows a vertical section of the press in a second modified form of the improvement. Fig. 6 shows a vertical section of the press with the third modified form of the improvement.

N is in Fig. 3 the frame of the electric press. It bears a vertical axle a, on which the electromotorfis arranged. The axle a is rotating by the action of the electric current in the known manner. (t t a are the wires to lead the electric current to the electromotor. On the axle a is fastened the fly-wheel a and the toothed wheel a, which gears with the toothed wheel (Z of the axle c. This axle has a screw-thread c, which gears with the screwnut 0 attached to the end b of the lever Z) Z). The lever b grips into the stamp 13 of the press.

The vertical axle c is supported by the spring 9 and is pressed upward, being not firmly arranged in its bearing c". It is pressed Serial No. 17,298. (No model.)

by the action of the spring 9 against the twoarmed lever h h, so that the end h is pressed down on the metallic seat 8.

The wires a a of the electric current are respectively fastened to the lever h and to the seat .9, so that the electric current is closed when the lever h is pressed down on its seat .9.

The working of the electric press is as follows: The electric current sets in motion the electromotor and the rotating axle a with the fly-wh eel a. By the gearing the vertical axle c is likewise set in motion, and the nut c of the lever b is screwed upward. The lever b and the punch 19 are moved downward until the pressing action begins. As soon as the resistance of the object to be pressed is so strong that it preponderates the tension of the spring g the axle o is moved downward and the lever h 71- is free from the action of the axle c. The weight of the arm h being greater than that one of the arm h causes the turning of the lever 7L, so that the electric circuit between lever h and seat 8 is interrupted. The electromotorfreceives no more electric current, and the pressing action of the punch 19 would cease if the mass of the rotating fly-wheel would not be strong enough to finish the pressing of the object.

It is clear that the safety of the good work depends upon the choice of the spring force g. Its strength determines thetime in which the press is driven by the electric power. Now it will be time to give an explanation for the illustrations Fig. 1 and Fig. 2, shown in form of a scheme.

Fig. 1 shows in a p 6 line the increasing resistance 20, which takes place during the pressing action of the press. In the beginning of the pressing action the resistance of the object to be pressed is smaller-as, for instance, at the point /a it possesses only the half of the force of the resistance at the point 7/, and at the end of the pressing action at o the resistance is the largest. It 10' Q02 are two measures for the force of the resistance, it is clear that I can choose the spring force g, so that in the point [3 of the pressing action if the resistance has reached the point '20 the interruption of the electric circuit takes IOO place and the resistance for finishing the pressing of the object must be overpowered by the force inertia of the fly-wheel.

Fig. 2 shows that more distinctly. The field .or plane N (P I P P shows the size of the work taken up by the flywheel. S desig nates the time in which the motor runs free without any pressing action. The pressing action begins at Q, and the electric current acts still further on the electromotor up to the point P In that moment the electric current is interrupted and the forces inertize of the fly-wheel work, alone. They have to overpower a labor L of the size of the plane P P P P. It is evident that the area of the plane L must be equal to the area of the plane N if one wants to be sure that the pressing is indeed finished by the forces inertise of the fiy-wheel.

Fig. I shows a modification of the arrangement. The Whole arrangement is the same as in Fig. 3, only the gearing mechanisms are different. There is only one vertical axle a, and this axle bears directly the Worm Z, which gears with a wheel m, the tooth-wheel n, and the sector-lever 0, which is in connection with the punch 19. Further, the axle a bears itself the spring g, which presses down the axle a. The lever h, which rests on the seat 8, has only one arm, and the axle a interrupts directly the electric circuit between It and s'when accordingly lifted. The action of this modification is clear without further explanation. In the essential it is the same as in Fig. 3.

Fig. 5shows a third modification. a is the axle of the electromotor f, which bears the fly-wheel a and has on its upper end the screw-thread t. The latter is inclosed by the hollow plug (1, which dips tightly in the cylinder 1", filled with water or another fluid. The cylinder r bears in its upper part the small piston 71 which is pressed down by a springg' and which has a pin h adapted to push against the lever h and to interrupt the electric circuit, as already mentioned before. The cylinder r is by the tube 3 in connection with the cylinder 6', in which the piston 77. slides up and downward. The piston 11 bears the pressing mechanism 19. The action is as follows: By the electric circuit the axle a, with fly-wheel a, is rotating, and the plug g, which is guided in the frame N, so that it can only slide up and downward without turning itself, presses the fluid of the cylinder 7' into the cylinder t, whereby the pressing mechanismp is moved downward until it touches the object to be pressed. The pressing action begins, and if the resistance of the object to be pressed is sostrong that the pres,- sure in the cylinder t and in the cylinder-n" is increased so much to lift the piston Hand to compress the spring 9 the electric circuit is interrupted and the action of the fly-wheel finishes thepressing operation. It is evident that by this arrangement the electric current causes at the beginning directly the pressing operation and that if the resistance is too strong it causes indirectly the finishing of the pressing operation by having given to the flywheel the necessary forces inertiae. It is not necessary by this arrangement to increase the action of the electric current to the end of the pressing operation and to aheight equal to the greatest resistance of the object to be pressed, but only to em ploy an electric current of middling power. By this arrangement the danger is avoided that aburning of the armature of the electromotor takes place which could not be avoided by the usual arrangements, whereas in the moment ofthe greatest strain of the motor the resistance ceases suddenly.

Fig. 6 shows a modification in which the interrupting mechanism is arranged directly above the pressing mechanism 10. The pressed stamp is, as seen from this figure, provided with a bore 19 on its upper part and a bore 13 of a smaller diameter, through which projects a pin 10 The latter rests with a collar 1" against a shoulder formed on the bottom of the-upper bore and is guided "in a mufi or a stufling-box r arranged in the interrupting mechanism. A spring g always tends to press the pin downward. The stamp is moved'up and down in the heretofore-mentioned manner regarding the Figs. 3 and 4,

whereby the current to the motor flows in the following manner: from'the positive line of a suitable electric source to one arm of the interrupting mechanism, from the other arm of the latterto one pole of the motor, through its armature, and from the other pole of the motor to the negative line. As soon as the stamp or head of the pressing mechanism is lowered so far down that the pin 19 touches the, material to be pressed the pin rises against the tension of the spring and opens the inter- :rupting mechanism, thus interrupting the current. Owing to the force of inertia the fly-wheel continues to rotate and causes the stamp still to descend and to press upon the material.

Having thus fully described the nature of this invention, what I desire to secure by Letters Patent of the United-States is In electrical presses, the combination of an electromotor, a fly-wheel rotated by this electromotor and a pressing mechanism, with a circuit-interrupting mechanism situated in the circuitof the electromotor, andmeans for automatically actuating the circuit-interrupting mechanism, when a certain pressure has been reached,substantially asdescribed and for the purpose set forth.

In witness whereof I have hereunto set my hand in presence of two witnesses.

OTTO KAMMERER. 

